Volunteers Help Terns Turn Corner

Tim Anderson spent much of his spring at a wildlife refuge in Seal Beach, guarding one of the few nesting spots for the endangered California least tern. At the sight of a hungry hawk or crow overhead, he’d scream until his throat ached and wave his shirt in the air, like a castaway signaling for help.

And by all accounts, his low-tech efforts, along with similar help from about 50 other Seal Beach-area volunteers, helped the least tern recover from a disastrous 1999.

According to official counts this year at the Seal Beach National Wildlife Refuge, about 200 baby least terns survived, the offspring of about 300 birds that built 140 nests in the sand. Only three of the birds died, and only three eggs were eaten by predators.

By contrast, last year all of the terns’ eggs and chicks were consumed by hawks, falcons and crows. Dozens of adult birds also died, bird-watchers said.

“People stepped up their vigilance to help this bird,” said Jack Fancher, coastal program chief for the U.S. Fish and Wildlife Service office in Carlsbad. “It really paid off.”

Fancher and officials at the Seal Beach refuge came up with the idea to ask for volunteer help. Fancher said he also asked for help at other nesting sites, but Seal Beach by far drew the largest numbers.

The birds have since flown back to Mexico. They migrate to California to breed.

Most of the credit for this year’s success, experts said, goes to Friends of the Seal Beach National Wildlife Refuge. The group of volunteers worked in shifts of four to six hours guarding NASA Island from dawn until dusk. (The predators are inactive at night.) The island, 4 acres of marsh grasses encircled by an electrified fence to keep out ground predators, is part of the Naval Weapons Station.

“We wanted to help, and we did,” said Bruce Monroe, co-chairman of the volunteer group. “And I think you can see that in how many of the birds survived.”

Anderson makes a living by giving trips in a boat through wetlands. His craft is modeled after a Cajun rice-harvesting boat. His flexible schedule allowed him to take chunks of four or more hours a day to stand guard at NASA Island.

Other volunteers would bring a book or a crossword puzzle to pass the time. Anderson most often brought a spyglass or binoculars and spent his time watching tiger beetles and other birds. Sometimes he’d visit in the morning, sometimes in the darkening hours; it depended on what he wanted to observe.

He said, though, that the least tern alone was enough to keep him from boredom; he watched the birds tuck their beaks under their feathers and tend their nests.

“The place is just wholly alive,” the 47-year-old Westminster resident said. “I watched all this life on a whole level. You see different things all day. The blooming algae. I was in heaven.”

Last year, poor survival rates were reported at many of the three dozen tern nesting sites throughout the state. At a Venice Beach nesting site, for example, no baby terns, of as many as 80 eggs, survived; one peregrine falcon killed them all in two days, officials said.

Nobody is exactly sure why it was such a bad year overall, but experts guess it was a mix of bad luck and a lack of human attention. This year, 774 least terns colonized the Venice site and 200 fledglings, from 625 eggs, survived. Crows and ravens ate many eggs.

“I think it’s a combination of predators and food supply, like anchovies,” said Kathy Keane, a biologist who specializes in least terns. She owns Keane Biological Consulting in Long Beach. “Sometimes the food supply is low. But that’s hard to document. It’s just really hard to tell why they suffer sometimes. I do know that last year was the worst year I’ve seen . . . since 1985.”

Although 2000 figures for other nesting sites are not yet tallied, experts say the results in Seal Beach are an encouraging sign, and bird-watchers are feeling relief. Keane said: “Seal Beach really . . . bodes well for the rest of the state.”

California least terns, which have yellow bills and legs and white patches on their foreheads, have been in trouble for years--largely because of loss of habitat. Normally, they would nest on any beach, but beginning in the early 1970s, they started running out of room as Southern California grew.

The birds were placed on the endangered species list and federal and state officials created nesting sites for them; there are six from Venice Beach to Huntington Beach.

But even with accommodations, there is an inherent problem with the nesting-site approach: “It concentrates the least terns all in one place to breed,” said Fancher, the Fish and Wildlife official.

“Normally, they wouldn’t be so concentrated. At their nesting sites, it makes them vulnerable, and prime targets to anything from cats to red foxes, to ravens and crows, to peregrine falcons. [Least terns] can survive in an urban environment, but we’ll always have to be watching.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Baby Boom

About 200 California least tern fledglings survived nesting this year at Seal Beach National Wildlife Refuge. Last year, the population plummeted.